Factsheet: Fluoride

WATER QUALITY DIVISION

INTRODUCTION carbonate formations generally having higher This factsheet provides basic information for concentrations. In addition, wells completed in private water well owners regarding fluoride in in deep water sources can have higher their well water. To determine if water is concentrations of fluoride than shallow wells or generally safe to drink, water test results are surface water supplies. Where calcium compared to the US Environmental Protection concentrations are high, fluoride dissolution is Agency (EPA) Primary Drinking Water inhibited. Regulations table of contaminants and the EPA Secondary Drinking Water Standards. The Fluoride is common in U.S. groundwater at above standards only apply to public water concentrations generally less than about 2 mg/L. systems, but the quality and health implications Less than 0.01% of U.S. water supplies have are the same for private well owners. In addition, fluoride concentrations greater than 4 mg/L. the Wyoming Department of Environmental Quality (WDEQ) has a set of standards (Water WHAT IS THE STANDARD FOR FLUORIDE IN Quality Rules and Regulations (WQRR) Chapter 8 GROUNDWATER? Table 1) for water quality based on class of use, Fluoride is regulated under the US EPA Primary including domestic, agriculture and livestock. Drinking Water Regulations. The US EPA has set Keep your analytical results and your sampling a maximum contaminant level for fluoride at 4 documentation with your well information for milligrams per liter (mg/L). future reference if there is a question about change in water quality. In addition, the EPA has set a secondary MCL for fluoride at 2 mg/L. Secondary MCLs are non- WHAT IS FLUORIDE? enforceable guidelines, and are set due to Fluoride is a common mineral in certain types of aesthetic (i.e. taste or odor) or cosmetic effects soils and rocks, especially in igneous rocks. (i.e. teeth discoloration). Fluoride is a stable ion of the gaseous element fluorine. It is highly reactive, and does not IS FLUORIDE IN MY WATER A HEALTH generally occur freely in nature, but combines CONCERN? readily with other elements (i.e. calcium and At low level concentrations, fluoride is believed phosphorous) into compounds called fluorides. to prevent tooth decay and strengthen teeth. Common fluoride minerals include, fluorspar, The American Dental Association (ADA) suggests cyrolite, and fluorapatite. Sodium fluoride the optimal fluoride level for tooth health is 0.7 minerals are soluble in water, other fluoride mg/L. minerals (i.e. calcium fluoride, aluminum fluoride, or magnesium fluoride) do not readily The EPA secondary MCL of 2 mg/L is based on the dissolve in water. potential for dental fluorosis (discoloration or weakening of teeth). Dental fluorosis only affects WHAT CAUSES FLUORIDE IN MY WATER? teeth prior to eruption from the gums, so the The level of fluoride in groundwater is heavily EPA recommends that children under the age of influenced by geology and groundwater 9 do not drink water containing more than 2 properties. Concentrations of fluoride can vary mg/L of fluoride. based on the type of rock, with granites and

MARCH 2018 WYOMING DEPARTMENT OF ENVIRONMENTAL QUALITY deq.wyoming.gov

FACTSHEET: FLUORIDE

Consumption of high levels of fluoride over time technical Series on Ground Water Quality, (greater than 4 mg/L) can cause fluoride Fluoride in Ohio’s Ground Water accumulation in the bones, leading to skeletal US Environmental Protection Agency, January 2011, fluorosis. Skeletal fluorosis involves pain and EPA 815-F-11-001, Questions and Answers on stiffness in the joints; severe cases can cause Fluoride Water Systems Council, Wellcare®, April 2016, damage to bone structure and calcification of Information for you about Well Water & ligaments. Fluoride World Health Organization, 2017, Guidelines for HOW DO I TEST FOR FLUORIDE IN MY WATER? Drinking Water Quality, Chapter 10, Chemical A list of certified labs can be found on the WDEQ Aspects Know Your Well Webpage (deq.wyoming.gov/wqd/know-your-well). Contact your selected laboratory for testing procedures and sample bottles.

WHAT CAN BE DONE TO TREAT MY WATER FOR FLUORIDE? The information below is intended as an information source only. The WDEQ suggests you discuss appropriate water treatment options with a qualified water treatment specialist, since other constituents in your water may affect the selection of the appropriate water treatment method.

If you have young children in the house and your fluoride level is greater than 2 mg/L you may wish to treat your water. Treatment is recommended for any domestic water supply greater than 4 mg/L. Because fluoride is not absorbed through the skin, point-of-use systems to treat water for drinking or cooking should be sufficient. Treatment options include reverse osmosis, activated alumina and distillation. Typical charcoal filtration systems do not remove fluoride from water.

REFERENCES Agency for Toxic Substances and Disease Registry, September 2003, ToxFAQsTM Fluorides, Hydrogen Fluoride, and Fluorine, CAS #7681-49- 4, 7664-39-3, 7782-41-4 Ohio Environmental Protection Agency, Division of Drinking and Ground Waters, February 2012,

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